What is the D.P.I when shooting large format

[marc_morris]

Can you tell me what is the size of the D.P.I when shooting j pegs on large format . I am

shooting on a Canon Eos Mark II N . When i look at image size in photo shop cs it is on

auto at 72 d.p.i , but what can i put it up to with out losing picture quality .

hope you can help ,

[adzy]

Marc, short answer, dpi matters only when u are printing. U can put anything in the raw converter window- 72, 320, 360, it doesnt matter.

 

When u print, find out from your printer what dpi they want.

 

Also, loads of threads on this topic on this site.

[anupam]

For a moment I thought you were shooting large format with a digital back! Anyway, DPI doesn't matter while shooting your Canon. But it would if you had a scanning back on a 4x5 camera.

[frank_dzambic]

As the others have already kind of said, all that matters is the number of pixels. How many inches of paper you spread those pixels out over will determine your dpi, or more correctly your ppi. What you're asking in your second question, though you probably don't realize it, is how big of a print can you make without losing quality. That's subjective. Make prints at various sizes until you make one big enough that you don't like the quality of it anymore, and you'll have your answer.

[paul -]

The camera supplies files that are 3,504 x 2,336 pixels, and not any any particular PPI (pixels per inch, not DPI which means dots per inch - DPI is a printer "thing"; it takes a number of colored ink dots to make a single pixel).<p>The only reason you see 72dpi is because your software is showing you an image that is<br> 48.6666 inches (3504/72) x 32.4444 inches (2336/72). If you want more pixels per inch, make a smaller print without interpolation.<p>Without interpolation, any file will give larger prints at lower PPI and smaller prints at larger PPI.<p>If you want to print with at least 300dpi without interpolating, you can print up to 11.68 inches x 7.78 inches. Get it?<p>Anyway, if you want Photoshop to display the file more to your liking, you can change the default display numbers by going into Edit>Preferences>Units & Rulers. This won't change the file in any way, it will only change the way it is displayed.

[awindsor]

Paul, PPI is an Adobe invention. While I agree it is a nice notion and does clarify the difference it came too much late. Dots per inch is used widely in exactly this context. Moreover the output resolutions for various continuous tone devices are specified in DPI. You almost always see scanner resolutions quoted as DPI for example. You just have to get use to the meaning of DPI being context sensitive.

[peterblaise]

.

 

PPI = picture elements per inch, a useful measurement in the "real world" of scanners and other digital capture devices. Does anyone know the ppi of their digital camera chip? I have scanners from 200ppi (flatbed) to 5,400ppi (for 35mm film).

 

DPI = dots per inch, a useful "real world" measurement when calculating print out dimensions or resolution of a display device. Inkjets? Epson input software expects (or resizes) input files of 360dpi; HP, Canon, Lexmark and other input software expects (or resizes) input files of 300dpi.

 

In the virtual world of image files as coming from a digital camera, neither "real world" measurement of ppi nor dpi matters.

 

It is STUPID for a camera maker to put a "real world" dpi measurement into the "virtual world" of image fles.

 

Ignore it in your camera.

 

Pay attention to ppi and dpi when specifing a new purhase for a scanner, camera chip, display or printer, or when preparing files for output to displays or printers, and then only observe or manipulate efective ppi in your printer or display control software.

 

Let us know what you do.

 

Good luck!

 

Peter Blaise peterblaise@yahoo.com http://www.peterblaise@yahoo.com/

[roger krueger]

DPI/PPI is only a useful image measurement at a given physical dimension. <br>

Except in matters of sizing for a final print it's better ignored.

<br><br>

72dpi @ 50" = 144dpi @ 25" = 1440 dpi @ 2.5"--it's still 3600 pixels in that dimension.

Pixel count is what matters. Print at a size that keeps you over 300 dpi for absolute best

results, over 200 dpi for still-quite-good results for most applications.

<br><br>

<i> PPI (pixels per inch, not DPI which means dots per inch - DPI is a printer "thing"; it

takes a number of colored ink dots to make a single pixel).</i>

<br><br>

DPI is NOT just a printer thing. Some folks are on a crusade to ram this redefinition of a

long-used term down our throats, but that doesn't make it so. "Correcting" everyone who

uses DPI in its accepted-for-decades meaning isn't adding information, it's merely adding

noise.

[briany]

man, we really need a FAQ

[ellis_vener_photography]

here is are the numbers for the same file at different resolutions. Notice that while the

physical size measured in inches changes as the resolution changes, the number of pixels

remains the same as does the overall file size.<div></div>

[ilkka_nissila]

Epsons definitely don't expect 360 ppi files, the newest ones (R800/R1800) have been noted to produce improved print quality when the user has supplied up to a 1000 ppi file. The native RGB res is probably 1440 ppi, or 720 ppi in lesser Epsons.

[roger krueger]

That says it all very cleary Ellis. Please keep it handy to repost every month or so as

needed.